how to find loaded dll path in VB6.0

[VB Developer]

Hi All,

I have a scenario where i'm using .net dll in VB6.0 application. I need to verify the .net dll location before using in VB6.0 to make sure that it is correct dll. so how to find the location("C:\Windows\Microsoft.NET\assembly\GAC_32\Test\v....") of dll using dll name(Test.dll). Thanks in advance

[Max187Boucher]

If the path is always the same but only the drive letter changes, then you could get the pc's main drive letter and just add the rest hard coded. If that is not the case, you can search pc (which could take a short to long time).

This searches for the first found file.

Private Declare Function SearchTreeForFile Lib "imagehlp" (ByVal RootPath As String, ByVal InputPathName As String, ByVal OutputPathBuffer As String) As Long

Private Function FindFile(FileName As String) As String
Const BufferLen As Long = 260
Dim sBuffer As String
Dim lRet As Long
Dim SystemDrive As String

  sBuffer = String(BufferLen, 0)
  SystemDrive = Environ("SystemDrive") & "\"
  
  lRet = SearchTreeForFile(SystemDrive, FileName, sBuffer)
  If lRet <> 0 Then FindFile = Left(sBuffer, InStr(1, sBuffer, Chr(0)) - 1)
End Function

Private Sub Command1_Click()
MsgBox FindFile("Test.dll")
End Sub

[techgnome]

I'm not sure why you would need it... the .NET DLL should be COM-visible, and thusly registered in the registry, so it shouldn't matter where it is.

-tg

[VB Developer]

I'm looking for this because need check the digital certificate of .net dll to make sure that .net dll is not replaced.

[fafalone]

I'm still not clear on whether the DLL is always in that directory or might be installed elsewhere. If it never moves, you can just use PathFileExists API call.

If it's always in the same subdirectory from the Windows directory, Environ("WINDIR") & "\Microsoft.Net\" ...

Or start a search from there using the search code someone posted above.

[Phill.W]

As techgnome said, you should be using COM-visible .Net assemblies so the only way you're going to find them is through the Registry. Your .Net project should explicitly specify all the GUIDs and Type Library IIDs that it exposes (if it doesn't, change it to do so).

Search the Registry under HKEY_CLASSES_ROOT\Typelib for the assembly's IID and version, then continue on down through LocaleId to the win32 subkey; the default value of this is the location of the .Net Assembly.

Here's an example from Microsoft's own stable, the Primary InterOp assembly for ADO 2 (on a 32-bit system; Wow64 makes life even more "interesting"):

HKEY_CLASSES_ROOT\
   {00000200-0000-0010-8000-00AA006D2EA4}\   (Interface ID)
      2.0\                                   (Version) 
         0\                                  (Locale) 
            win32\
               @ = "%CommonProgramFiles%\System\ado\msado20.tlb"

Regards, Phill W.

[VB Developer]

after long time, started resuming this further

Path of dll is decided by customer during installation.